Shawn got laid off a couple years ago and the couple decided to start working on iPhone and iPad apps for toddlers.

Since then, they've sold their cars, cashed out his 401(k), and avoided taking more sure-fire jobs.

"I'll retire when I die," says Shawn.

Streitfeld says the couple has lost about $200,000 in savings and potential earnings.

So far, it hasn't been worth it: the toddler apps have only brought in about $5,000 in sales.

Streitfeld also tells the story of Ethan Nicholas. Nicholas's first app for the iPhone did very well, and it made him a millionaire. He used the money to create more apps and a pair of startups. Since then, none of his apps or startups have done nearly so well.

According to a very small survey of 252 gaming developers from Streaming Color Studios, 25% of all game apps make less then $200 in their lifetime, 25% make more than $30,000, and just 4% make more than a million.

So here's a reminder: Software startups – like almost all startups – are very hard, and usually fail.